Modular architecture pet decoder for ATM networks

Abstract

A PET decoder for an ATM network has a modular architecture including a processing unit having various memories and a processing pipeline for constructing from a block of m data of a certain number of bits, a square matrix A based on a vector D of relative points over the Galois field. The processing pipeline also decomposes by triangular factorization the square matrix A and solves the subsystem of equations by simple substitution. The decoder also includes a control unit interfacing with the ATM network, a programmable parallel processor, a random access memory and the processing unit.

That which is claimed is:  
     
       1. A modular PET decoder for an ATM network comprising: 
       a processing unit comprising a first memory for storing data for decoding processing, a second memory for storing intermediate results of decoding processing, and a processing pipeline, the processing pipeline for:  
       constructing, starting from a block of m digital data of a predefined number of bits, an m×m square matrix A based on a vector of relative points over a Galois field to which an m number of packets of coded information received at a decoder input refer to based upon header bits of the m packets,  
       decomposing by a triangular factorization of the square m×m matrix A according to a scheme A=LU, where L is a resulting lower triangular matrix and U is a resulting upper triangular matrix into which the square matrix A is decomposed and from which UX=Y and LY=B, where B is a vector of polynomial values decoded as a function of a certain offset stored in header bits of the input packets,  
       solving the systems LY=B and UX=Y by substitution; and  
       a control unit connected to said processing unit for interfacing to the ATM network.  
     
     
       2. A modular PET decoder according to claim  1 , further comprising a programmable parallel processor connected to said control unit. 
     
     
       3. A modular PET decoder according to claim  2 , further comprising a random access memory connected to said control unit. 
     
     
       4. A modular PET decoder according to claim  3 , wherein said control unit comprises: 
       a first block for interfacing with the ATM network; and  
       a second block interfacing with said programmable parallel processor and transferring a predefined number of bits at each clock pulse.  
     
     
       5. A modular PET decoder according to claim  4 , wherein said control unit further comprises: 
       a central unit; and  
       a header reader controlled by said central unit sorting each of the m digital data in the related block depending on an address value provided by said central unit.  
     
     
       6. A modular PET decoder according to claim  5 , wherein said control unit further comprises: 
       a memory interface preventively arbitrating possible conflicts among write cycles every time certain data is output by the first interface block with the ATM network, and read cycles of said random access memory by said central unit.  
     
     
       7. A modular PET decoder according to claim  6 , wherein said control unit further comprises: 
       an offset removing block eliminating an effect introduced in the data during a coding phase, and outputting data of n+1 bits from two input data of n bits each.  
     
     
       8. A modular PET decoder according to claim  6 , wherein said control unit further comprises: 
       an output buffer transferring data toward said processing unit;  
       an input buffer for decoded data received from said processing unit; and  
       a third buffer containing data relative to a priority table decoded by said processing unit and made readable by said central unit.  
     
     
       9. A modular PET decoder according to claim  8 , wherein said control unit further comprises: 
       a common bus operatively connected to be shared by said central unit, said memory interface modules, said interface blocks, and said header reader block for allowing a simultaneous acquisition of data thereby.  
     
     
       10. A modular PET decoder according to claim  1 , wherein said control unit is monolithically integrated with said processing unit. 
     
     
       11. A modular PET decoder according to claim  1 , wherein said first memory comprises a read only memory. 
     
     
       12. A modular PET decoder according to claim  1 , wherein said second memory comprises a static memory. 
     
     
       13. A modular PET decoder for an ATM network comprising: 
       a processing unit comprising a first memory for storing data for decoding processing, a second memory for storing intermediate results of decoding processing, and a processing pipeline, the processing pipeline for:  
       constructing, starting from a block of m digital data of a predefined number of bits, an m×m square matrix A based on a vector of relative points over a Galois field to which an m number of packets of coded information received at a decoder input refer to based upon header bits of the m packets,  
       decomposing by a triangular factorization of the square m×m matrix A according to a scheme A=LU, where L is a resulting lower triangular matrix and U is a resulting upper triangular matrix into which the square matrix A is decomposed and from which UX=Y and LY=B, where B is a vector of polynomial values decoded as a function of a certain offset stored in header bits of the input packets, and  
       solving the systems LY=B and UX=Y by substitution;  
       a programmable parallel processor; and  
       a control unit connected to said processing unit and monolithically integrated therewith for interfacing to the ATM network, said control unit comprising  
       a first block for interfacing with the ATM network, and  
       a second block interfacing with said programmable parallel processor and transferring a predefined number of bits at each clock pulse.  
     
     
       14. A modular PET decoder according to claim  13 , further comprising a random access memory connected to said control unit. 
     
     
       15. A modular PET decoder according to claim  14 , wherein said control unit further comprises: 
       a central unit; and  
       a header reader controlled by said central unit sorting each of the m digital data in the related block depending on an address value provided by said central unit.  
     
     
       16. A modular PET decoder according to claim  15 , wherein said control unit further comprises: 
       a memory interface preventively arbitrating possible conflicts among write cycles every time certain data is output by the first interface block with the ATM network, and read cycles of said random access memory by said central unit.  
     
     
       17. A modular PET decoder according to claim  16 , wherein said control unit further comprises: 
       an offset removing block eliminating an effect introduced in the data during a coding phase, and outputting data of n+1 bits from two input data of n bits each.  
     
     
       18. A modular PET decoder according to claim  16 , wherein said control unit further comprises: 
       an output buffer transferring data toward said processing unit;  
       an input buffer for decoded data received from said processing unit; and  
       a third buffer containing data relative to a priority table decoded by said processing unit and made readable by said central unit.  
     
     
       19. A modular PET decoder according to claim  18 , wherein said control unit further comprises: 
       a common bus operatively connected to be shared by said central unit, said memory interface modules said interface blocks, and said header reader block for allowing a simultaneous acquisition of data thereby.  
     
     
       20. A modular PET decoder according to claim  13 , wherein said first memory comprises a read only memory. 
     
     
       21. A modular PET decoder according to claim  13 , wherein said second memory comprises a static memory. 
     
     
       22. A method for PET decoding in an ATM network comprising the steps of: 
       providing a processing unit comprising a first memory for storing data for decoding processing, a second memory for storing intermediate results of decoding processing, and a processing pipeline; and  
       operating the processing pipeline for:  
       constructing, starting from a block of m digital data of a predefined number of bits, an m×m square matrix A based on a vector D of relative points over a Galois field to which an m number of packets of coded information received at a decoder input refer to based upon header bits of the m packets,  
       decomposing by a triangular factorization of the square m x m matrix A according to a scheme A=LU, where L is a resulting lower triangular matrix and U is a resulting upper triangular matrix into which the square matrix A is decomposed and from which UX=Y and LY=B, where B is a vector of polynomial values decoded as a function of a certain offset stored in header bits of the input packets, and  
       solving the systems LY=B and UX=Y by substitution.